A rough study of this composition is in the Dolbadarn sketchbook (Tate D02153; Turner Bequest XLVI 107) and a large colour study, perhaps the commencement of a finished watercolour, is Tate D04167 (Turner Bequest LXX P). If Turner did intend to make a watercolour of this subject it would have been the only one of the Fonthill set to be in an upright as opposed to a horizontal format; for another upright composition sketched at Fonthill see D02181; Turner Bequest XLVII 4).
The tonal arrangement of the design follows a scheme that Turner had experimented with in about 1794–5 in his watercolour of Valle Crucis Abbey (Tate D00703; Turner Bequest XXVIII R), in a study of the Entrance to the Great Hall of the Bishop’s Palace, St David’s of 1795 (Tate D00688; Turner Bequest XXVIII C) and in other works of 1795–6, in which a dark foreground is separated from a high-toned distance or sky by a stark horizontal division. John Gage suggests1 that the process was inspired by the methods of Claude Lorrain (1604/5–1682) as analysed by the painter Benjamin West (1738–1820) after examining William Beckford’s two ‘Altieri’ Claudes in London earlier in 1799, but the existence of Turner’s experiments from several years earlier suggests that he had already evolved the idea as a compositional and, indeed, conceptual principle.
See Gage 1969, p.31.